Underfill material and method for manufacturing semiconductor device using the same

Abstract

An underfill film material and a method for manufacturing a semiconductor device using the same which enables voidless mounting and favorable solder bonding properties are provided. An underfill material is used which contains an epoxy resin, an acid anhydride, an acrylic resin and an organic peroxide, the underfill material exhibits non-Bingham fluidity at a temperature ranging from 60° C. to 100° C., a storage modulus G′ measured by dynamic viscosity measurement has an inflection point in an angular frequency region below 10E+02 rad/s, and the storage modulus G′ in the angular frequency below the inflection point is 10E+05 Pa or more and 10E+06 Pa or less. This enables voidless packaging and excellent solder connection properties.

The invention claimed is: 
     
       1. An underfill material applied to a semiconductor chip having a solder-tipped electrode formed thereon before mounting the semiconductor chip onto an electronic component having a counter electrode facing the solder-tipped electrode, wherein
 the underfill material comprises an epoxy resin, a curing agent, an acrylic resin, and an organic peroxide, 
 a ratio of the total mass of acrylic resin and organic peroxide to the total mass of epoxy resin and curing agent is in a range of 7:3 to 4:6, 
 the underfill material exhibits non-Bingham fluidity at a temperature ranging from 60° C. to 100° C., and 
 a storage modulus G′ measured by dynamic viscosity measurement has an inflection point in an angular frequency region below 10E+02 rad/s and the storage modulus G′ in the angular frequency below the inflection point is 10E+05 Pa or more and 10E+06 Pa or less. 
 
     
     
       2. The underfill material according to  claim 1 , wherein
 a dynamic viscosity η′ measured by dynamic viscosity measurement is inversely proportional to the angular frequency below the inflection point with a gradient of 10 raised to the power of 1. 
 
     
     
       3. The underfill material according to  claim 2 , wherein the storage modulus G′ in the angular frequency below the inflection point is constant. 
     
     
       4. The underfill material according to  claim 1 , wherein
 the storage modulus G′ in the angular frequency below the inflection point is constant. 
 
     
     
       5. The underfill material according to  claim 1 , wherein
 the epoxy resin is a glycidylether epoxy resin, and 
 the curing agent is an alicyclic acid anhydride. 
 
     
     
       6. The underfill material according to  claim 2 , wherein
 the acrylic resin is a fluorene acrylate, and 
 the organic peroxide is a peroxy ketal. 
 
     
     
       7. The underfill material according to  claim 4 , wherein
 the epoxy resin is a glycidylether epoxy resin, and 
 the curing agent is an alicyclic acid anhydride. 
 
     
     
       8. The underfill material according to  claim 1 , wherein
 the acrylic resin is a fluorene acrylate, and 
 the organic peroxide is a peroxy ketal. 
 
     
     
       9. The underfill material according to  claim 2 , wherein
 the epoxy resin is a glycidylether epoxy resin, and 
 the curing agent is an alicyclic acid anhydride. 
 
     
     
       10. The underfill material according to  claim 4 , wherein
 the acrylic resin is a fluorene acrylate, and 
 the organic peroxide is a peroxy ketal. 
 
     
     
       11. The underfill material according to  claim 5 , wherein
 the acrylic resin is a fluorene acrylate, and 
 the organic peroxide is a peroxy ketal. 
 
     
     
       12. A method for manufacturing a semiconductor device comprising:
 a mounting step of mounting a semiconductor chip onto an electronic component, the semiconductor chip having a solder-tipped electrode formed thereon and an underfill material applied to the surface of the electrode, and the electronic component having a counter electrode facing the electrode, and 
 a thermocompression bonding step of thermally compressing the semiconductor chip and the electronic component, wherein 
 the underfill material comprises an epoxy resin, a curing agent, an acrylic resin, and an organic peroxide, a ratio of the total mass of acrylic resin and organic peroxide to the total mass of epoxy resin and curing agent is in a range of 7:3 to 4:6, the underfill material exhibits non-Bingham fluidity at a temperature ranging from 60° C. to 100° C., a storage modulus G′ measured by dynamic viscosity measurement has an inflection point in an angular frequency region below 10E+02 rad/s, and the storage modulus G′ in the angular frequency below the inflection point is 10E+05 Pa or more and 10E+06 Pa or less.